Qilu Pharmaceutical Presents Updated Phase I Clinical Data of QLS31905, a CLDN18.2/CD3-Targeted T Cell Engager, at ASCO 2025

Recently, at the 2025 American Society of Clinical Oncology（ASCO）At the annual meeting,Updated Results of Qilu Pharmaceutical's QLS31905 Phase I Clinical Study in Advanced Solid Tumors Presented in Poster Format。

QLS31905 is a bispecific T-cell engager independently developed by Qilu Pharmaceutical, targeting Claudin18.2/CD3. It can bind to Claudin18.2 on the surface of tumor cells and CD3 on the surface of T cells, recruiting and activating T cells near the tumor cells to continuously kill and lyse the tumor cells. The Phase I clinical study of QLS31905 explored the safety, tolerability, and preliminary anti-tumor activity of the drug in patients with advanced solid tumors. The principal investigator was Professor Lin Shen from Peking University Cancer Hospital.

This study is divided into two phases: dose escalation and dose expansion. The dose escalation phase adopts an accelerated titration and i3+3 study design, with the primary endpoint being dose-limiting toxicity.（DLT）And Maximum Tolerated Dose（MTD）. The primary endpoint of the dose expansion phase is the objective response rate.（ORR）, and the secondary endpoint is the disease control rate.（DCR）、Progression-Free Survival（PFS）, Overall Survival（OS）The preliminary results of the study were presented in a poster at the European Society for Medical Oncology Immuno-Oncology Congress held in December 2023.

The updated data published this time is as of July 2024, with a total of 79 subjects who had previously failed treatment, including 43 gastric cancer and 26 pancreatic cancer patients. More than half of the subjects（61.8%）Have received no less than two lines of prior anti-tumor treatments.

In terms of safety, DLT did not occur within the dosage range of 0.5ug/kg~1200ug/kg qw or q2w, and MTD was not reached. ≥3 grade treatment-related adverse events occurred.（TRAE）In China, the incidence of TRAE ≥3% is lymphocyte count decrease.（21.5%）, Elevated γ-Glutamyl Transferase（3.8%）、Decreased neutrophil count（3.8%）, Anemia（3.8%）, Cytokine Release Syndrome（3.8%）All cytokine release syndromes eventually healed/recovered completely. No TRAE led to death.

In terms of efficacyAmong the 33 Claudin18.2-positive subjects in the 350~1200 μg/kg q2w dose group, 6 subjects achieved partial response.（PR）, including 3 patients with gastric cancer and 3 patients with pancreatic cancer. The ORR reached 18.18%, and the DCR reached 87.88%. The median PFS and median OS were 4.21 months and 9.53 months, respectively. Among the 19 patients with gastric cancer, the ORR, DCR, median PFS, and median OS were 15.79%, 89.47%, 4.40 months, and 9.20 months, respectively. For the 12 patients with pancreatic cancer, the ORR, DCR, median PFS, and median OS were 25.00%, 91.67%, 3.94 months, and not reached, respectively. The exposure of QLS31905 was linear with the dosing amount, and there was no accumulation trend after multiple doses.

In summary, QLS31905 demonstrated good safety and tolerability and showed promising efficacy in patients with Claudin18.2-positive advanced gastrointestinal tumors. Currently, the phase II clinical trial of QLS31905 is underway.

Editorial Responsibility | Yong

Proofread by Jiebolian |

1.https://mp.weixin.qq.com/s/HarOBvdde26Knd7EYvUwUA

Dian Dian "Share”、“Like" and "In view"，Give me a little recharge, please~